1. Field of the Invention
The invention relates to document processing, document imaging, and magnetic ink character recognition. The invention further relates to hand-operated document readers/imagers, and to methods and systems for restraining a document during processing with a hand-operated document reader/imager to avoid document skew.
2. Background Art
A typical document processing system includes a feeder and a separator in the document-feeding portion of the system, and a series of roller pairs or belts in the document-transporting portion of the system. In the feeding portion of the system, the feeder acts with the separator to feed documents singly, in order, from a stack. In the transporting portion of the system, the roller pairs and/or belts convey the documents, one at a time, past other processing devices such as readers, printers, and sorters that perform operations on the documents. The feeder is typically a feed wheel, but may take other forms. The separator may be a wheel, but also may take other forms such as a belt. Further, the components in the transporting portion of the system may take a variety of forms.
In addition to large document processing systems that handle stacks of documents, smaller systems also exist. These smaller document processing systems may handle smaller stacks of documents, or may even handle single documents, fed one at a time. There are also hand-operated document readers/imagers.
Banks, credit unions, and other financial institutions use document processing systems to regularly process checks, deposit slips, and other types of bank documents in order to execute financial transactions efficiently. Document processing systems have therefore become quite prevalent in the industry. Typically, information is printed on these documents in magnetic ink which can be read both by the human eye and a computer. This form of printing is read by a process called magnetic ink character recognition (MICR). As part of the recognition process, a MICR magnetic read head is used to read the information printed on the document.
Conventional approaches to MICR reading and recognition generally involve determining peak position information for a waveform generated by a single gap magnetic read head. This peak information typically includes information regarding the amount of time between the peaks of each character. Knowledge of the velocity of the document (and thus, the velocity of the characters which are printed on the document) allows this time information to be converted into distance information, which can be compared to the MICR character peak profiles as contained in ANS X9.100-20-2006 (formerly published as X9.27) “Print and Test Specifications for Magnetic Ink Printing (MICR)” as published by Accredited Standards Committee X9, Inc., Annapolis, Md., United States. Based on the design of the standard E-13B character set, in order that a MICR reader reliably read with a high correct character read rate and with a very low substitution rate, the document velocity must be precisely known during reading or otherwise be speed-controlled so that it does not vary.
These conventional approaches are acceptable when the velocity of the document is either known or can be controlled. In fact, conventional approaches to MICR typically involve rather complex scheines for controlling the velocity of the document or attempting to measure its velocity at different times as the document moves past the MICR read head. There has also been an approach to MICR reading and recognition that utilizes a dual gap read head to eliminate the need for precise knowledge or control of the document velocity.
In a hand-operated document reader/imager, the document is placed on a base and the MICR/image device is moved over the document from right to left, which is the traditional direction of larger document readers. During this movement, the MICR characters are recognized and the front image of the document is captured.
In more detail, the operational sequence of a manually operated linear check or document scanning device is as follows. A check or document is positioned on the bed of the device. The module that holds the contact image sensor and the magnetic read head is moved across the check or document, with the module being guided by a linear rod. The magnetic read head reads the MICR code line at the bottom of the document, and the contact image sensor scans the document. Data from both devices are passed to the electronics of the system for processing.
In order for the image sensor and magnetic read head to properly read the check or document, the speed of the module must be known over the entire length of the item being scanned. The speed of the scan can be measured by any one of a number of speed measuring devices. The greater the variation of speed, the more sophisticated, and therefore more expensive, the electronics must be, as well as the greater the chance of error.
The contact image sensor has a maximum speed limit, beyond which it will fail to operate properly. And, the MICR reader has a minimum speed limit, below which it cannot reliably operate. Accordingly, the speed of the scan must remain between these limits.
There is a 0.010 inch gap between the contact image sensor and the bed of the device. The check or document must be held firmly in place as the contact image sensor and magnetic read head are scanned over the document. If the check or document moves, an unusable image will result, such as a skewed image, and this situation will negatively impact the processing flow. Document movement during scanning tends to occur with checks or documents that have folds, creases, dog ears, or other mutilations. In general, any portion of the document that sits higher than the 0.010 inch gap will create friction against the contact image sensor and result in check or document movement.
The MICR read head is actually in contact with the document during scanning, and this friction also may skew the check or document, resulting in misreads and/or no reading of the MICR code line.
In existing document handling equipment, the only way that the check or document may be restrained is by any number of conventional clamping methods that restrain the document from both sides; however, in a scanning/reading system, the side of the document being scanned needs to be unobstructed.
For the foregoing reasons, there is a need for an improved method and system for providing document retention wherein the side of the document being scanned is not obstructed.